Monday saw some bad news for the snow crab industry in Newfoundland and Labrador.

According to a Department of Fisheries and Oceans (DFO) snow crab stock assessment, released Monday, what was once the world's largest snow crab fishery, is now seeing substantial decline.

"It's not a good news story ... the scale of this fishery is a big fishery," Darrell Mullowney, DFO's snow crab assessment lead for the N.L. region, said.

"In the long-term outlook on the broad scale, our pre-recruit index for all the compilation of areas from southern Labrador down to the south coast, has been at its lowest observed level in the past three years."

The overall exploitable biomass — or crab available to the fishery — has declined by 80 per cent since 2013, with an overall decline of 40 per cent from 2015-16.

"It's terrible, terrible news for people in the industry," Keith Sullivan, president of the Fish, Food and Allied Workers Union, told CBC Radio's The Broadcast.

"It's terrible news for our province when we hear that the biomass of all those stocks are down of our most valuable fishery in the province."

Warming waters

The predominant force for what Mullowney called a "pretty pessimistic" view of the fishery is climate and ecosystem changes and warming waters, a reason for shrimp's declining stock in Area 6, too.

Snow crab are closely related to the ocean's climate. The physical environment affects them at every stage of life with temperatures affecting growth rates, Mullowney said. Survival rates are highest in early life under cold conditions.

Darrell Mullowney

DFO's Darrell Mullowney says consultations will be held with fish harvesters and department managers before 2017 quotas are set. (Philippe Grenier/CBC)

"Throughout the last decade or more we've experienced warming conditions, a general warming trend, and this has been unfavourable for snow crab productivity. We've been experiencing a long term decline in this stock."

'In 2016 the fishery catch rates were at or near historical lows across all NAFO divisions' - Darrell Mullowney

Mullowney said projections for the Grand Bank are particularly alarming.

"The Grand Bank has been a productive area for snow crab for quite some time. This has been the world's largest snow crab fishery for a decade or more," he said.

"Fishery catch rates have declined this past year ... and in fact, in 2016 the fishery catch rates were at or near historical lows across all NAFO [Northwest Atlantic Fisheries Organization] divisions."

Sullivan echoed the assessment's findings and pointed to environmental conditions, and not overfishing, as reason for the decline.

"When it comes to crab, we don't harvest any females. We only take large male crabs. So it's a really clean fishery and if the environment was consistent, we'd certainly have a sustainable fishery." 

Global decline

While Mullowney said the declines are significant, they are not unexpected. 

"On the global scale, snow crab stocks are on the decline and they're generally on the decline in their southern most areas," he said.

"Newfoundland and Labrador and Alaska have essentially been the biggest fisheries for quite some time, and both of these stocks have undergone substantial declines in recent years." 

​DFO will meet with and provide advice to harvesters in first half of March, Mullowney said.

Advice from harvesters and the science behind the assessment will be given to senior managers to develop 2017 quotas and other management measures.

"The magnitude of this in terms of socioeconomics I can't really quantify," Mullowney said.

With files from The Broadcast